1. Field of the Invention
This invention relates to a semiconductor apparatus including a semiconductor device, used for ultra-high frequency signal processing of several GHz or more, or high-speed optical communication of several Gbps or more.
2. Description of the Related Art
Structure of a conventional semiconductor apparatus will now be briefly described.
The conventional semiconductor apparatus has a structure in which a semiconductor device is mounted on a dielectric board and is surrounded by a dielectric ring, with a metal cover mounted on the dielectric ring so as to cover the semiconductor device. Plural external electrodes for connecting with other external devices are arranged on the dielectric board. A thin metal wire is connected to the semiconductor device, and the thin metal wire is electrically connected with the external electrodes via wiring arranged on the dielectric board.
On a back side of the dielectric board having the semiconductor device mounted thereon, a metal plate for radiation is bonded, and plural through holes are formed in the dielectric board so as to connect this metal plate with the semiconductor device.
Literature 1: JP-A-5-129462
Literature 2: JP-A-7-50362
However, in the conventional semiconductor apparatus, the wiring connecting the semiconductor device with the external electrodes is formed by a conductive layer formed on the dielectric board and a single through hole, as disclosed in JP-A-7-50362. In this structure, since the conductive layer and the through hole are at right angles to each other, large parasitic capacitance is generated in the wiring. Therefore, there is a problem in that input/output of a particularly high-frequency signal between the semiconductor apparatus and an external device is difficult.